Initial commit: add .gitignore and README

.venv/lib/python3.12/site-packages/mypy/test/testipc.py

@@ -0,0 +1,119 @@
+from __future__ import annotations
+
+import sys
+import time
+from multiprocessing import Queue, get_context
+from unittest import TestCase, main
+
+import pytest
+
+from mypy.ipc import IPCClient, IPCServer
+
+CONNECTION_NAME = "dmypy-test-ipc"
+
+
+def server(msg: str, q: Queue[str]) -> None:
+    server = IPCServer(CONNECTION_NAME)
+    q.put(server.connection_name)
+    data = ""
+    while not data:
+        with server:
+            server.write(msg)
+            data = server.read()
+    server.cleanup()
+
+
+def server_multi_message_echo(q: Queue[str]) -> None:
+    server = IPCServer(CONNECTION_NAME)
+    q.put(server.connection_name)
+    data = ""
+    with server:
+        while data != "quit":
+            data = server.read()
+            server.write(data)
+    server.cleanup()
+
+
+class IPCTests(TestCase):
+    def setUp(self) -> None:
+        if sys.platform == "linux":
+            # The default "fork" start method is potentially unsafe
+            self.ctx = get_context("forkserver")
+        else:
+            self.ctx = get_context("spawn")
+
+    def test_transaction_large(self) -> None:
+        queue: Queue[str] = self.ctx.Queue()
+        msg = "t" * 200000  # longer than the max read size of 100_000
+        p = self.ctx.Process(target=server, args=(msg, queue), daemon=True)
+        p.start()
+        connection_name = queue.get()
+        with IPCClient(connection_name, timeout=1) as client:
+            assert client.read() == msg
+            client.write("test")
+        queue.close()
+        queue.join_thread()
+        p.join()
+
+    def test_connect_twice(self) -> None:
+        queue: Queue[str] = self.ctx.Queue()
+        msg = "this is a test message"
+        p = self.ctx.Process(target=server, args=(msg, queue), daemon=True)
+        p.start()
+        connection_name = queue.get()
+        with IPCClient(connection_name, timeout=1) as client:
+            assert client.read() == msg
+            client.write("")  # don't let the server hang up yet, we want to connect again.
+
+        with IPCClient(connection_name, timeout=1) as client:
+            assert client.read() == msg
+            client.write("test")
+        queue.close()
+        queue.join_thread()
+        p.join()
+        assert p.exitcode == 0
+
+    def test_multiple_messages(self) -> None:
+        queue: Queue[str] = self.ctx.Queue()
+        p = self.ctx.Process(target=server_multi_message_echo, args=(queue,), daemon=True)
+        p.start()
+        connection_name = queue.get()
+        with IPCClient(connection_name, timeout=1) as client:
+            # "foo bar" with extra accents on letters.
+            # In UTF-8 encoding so we don't confuse editors opening this file.
+            fancy_text = b"f\xcc\xb6o\xcc\xb2\xf0\x9d\x91\x9c \xd0\xb2\xe2\xb7\xa1a\xcc\xb6r\xcc\x93\xcd\x98\xcd\x8c"
+            client.write(fancy_text.decode("utf-8"))
+            assert client.read() == fancy_text.decode("utf-8")
+
+            client.write("Test with spaces")
+            client.write("Test write before reading previous")
+            time.sleep(0)  # yield to the server to force reading of all messages by server.
+            assert client.read() == "Test with spaces"
+            assert client.read() == "Test write before reading previous"
+
+            client.write("quit")
+            assert client.read() == "quit"
+        queue.close()
+        queue.join_thread()
+        p.join()
+        assert p.exitcode == 0
+
+    # Run test_connect_twice a lot, in the hopes of finding issues.
+    # This is really slow, so it is skipped, but can be enabled if
+    # needed to debug IPC issues.
+    @pytest.mark.skip
+    def test_connect_alot(self) -> None:
+        t0 = time.time()
+        for i in range(1000):
+            try:
+                print(i, "start")
+                self.test_connect_twice()
+            finally:
+                t1 = time.time()
+                print(i, t1 - t0)
+                sys.stdout.flush()
+                t0 = t1
+
+
+if __name__ == "__main__":
+    main()